On Friday, Special Counsel Robert Mueller charged 13 Russians for waging “information warfare” against the United States by using online ads and fake social media profiles to influence the 2016 elections. The Russians were associated with the Internet Research Agency, a notorious “troll farm” in St. Petersburg. The indictments came on the heels of America’s intelligence chiefs warning Congress earlier this month that Russia is actively trying to interfere with the 2018 elections using the same methods it did in 2016.

Despite all the recent months’ revelations about the Russian effort, Congress so far has done nothing to improve the protections against election spending by Russia and any potential copycats abroad. But we don’t have to leave the last word to a do-nothing Congress. California can take steps now to protect its own elections from meddling by foreign powers.

If the Golden State crafts strong protections, then it could set a nationwide standard — as it has done in other policy areas such as auto emissions.

The state should demand digital platforms create a public database of all advertisements that mention candidates or legislative issues — something TV and radio stations already do. And ad sellers should be required to make reasonable efforts to identify and block illegal foreign purchases of campaign ads. Because the threat of foreign intervention — by Russia, but also by North Korea, Iran, or even non-state actors like the Islamic State — is very real.

California has already shown leadership with the Disclose Act, requiring disclaimers for political ads on social media feeds. Rules such as this make it harder for Russian operatives to buy ads while pretending to be Americans. But even California’s forward-thinking policymaking has not yet gone far enough.

By now, the refrain is familiar. As part of its campaign to sow discord during the 2016 elections, the Russian government directed an army of Internet trolls to buy misleading, targeted ads on a variety of social media and Internet platforms. Ads purported to come from activists in movements such as Black Lives Matter or from Second Amendment enthusiasts, criticizing or praising presidential candidates. One of the operators of the “San Diego for Bernie Sanders” Facebook page suspected Russian mischief in March of 2016 when the page was suddenly flooded with posts attacking Hillary Clinton. His hunch wasn’t confirmed until the platforms revealed Russian meddling months after the election.

While regulating ads won’t directly address the issue of unpaid posts, it could make unpaid posts less effective, because advertisers use ads to drive audiences to unpaid content. For example: Facebook estimated that 11.4 million users saw Russia-linked paid ads on its platform. But users who clicked “like” or “share” on one of an account’s promoted posts were automatically, and possibly unknowingly, subscribed to follow that advertiser’s account. Once they were subscribed, that advertiser’s unpaid posts appeared in their news feeds. Approximately 126 million Facebook users saw unpaid posts from the Russia-linked accounts.

Asking whether these campaigns influenced the outcome of the election misses the point. They violate the spirit of laws designed to protect the political process from the influence of foreign powers. In the Federalist Papers, Alexander Hamilton wrote about preventing foreign nations from gaining “an improper ascendant in our councils.” The law has banned foreign spending on elections for half a century. In short, leaders have long believed that our sovereignty depends on protection from foreign meddling generally, and spending in elections specifically.

The problem is that our campaign finance system needs updates for a world where everything moves online — especially propaganda. Congress last updated the rules for election ads in 2002, years before iPhones, Facebook and Twitter. Internet ads remain less regulated than those on television and radio.

California, of course, has outsize influence on Silicon Valley. The state has an opportunity to lead when it comes to passing substantive reforms for the Internet. Social media companies should have a legal obligation to do their due diligence and make their best effort at figuring out whether foreign actors are behind certain ad buys. “Trust us” just doesn’t cut it anymore. And they need to maintain databases of ad buys so regulators and the American public can get a full accounting of campaign spending online.

Once states like California put these guidelines in place — and legislators in New York and Maryland have introduced bills along these lines — the tech companies will have a trickier time arguing against any federal moves demanding a similar degree of accountability. After all, if they’re already complying with state regulations, their resistance to similar national regulations should diminish.

To be sure, reining in ad buys only addresses part of the problem — elections are also vulnerable to cyberattacks, for example.

Our adversaries are tenacious, and even the best-crafted campaign finance laws will not prevent all attempts at foreign interference. But taking steps to shield our political process from foreign powers will help bring a new degree of transparency to online advertising, which could act as a preventive deterrent to those wishing to influence our democracy. California already has taken the first steps at helping re-establish trust in our elections. Time to finish the job.